1. Field of the Invention
The present invention relates to a rotation angle sensing assembly including sensor attaching structure, to a variable valve mechanism for an internal combustion engine having such attachment structure, and to a vehicle incorporating the same. More particularly, the present invention relates to an attachment structure in which an outer race of a bearing is secured with a reduction gear and an inner race of the bearing is secured to a supporting wall provided on a cylinder head, and a rotation angle sensor is secured integrally to the reduction gear, and to a vehicle incorporating the same.
2. Description of the Background Art
There is a known rotation angle sensor attaching structure provided on a variable valve mechanism for an internal combustion engine, a rotation angle detection object shaft is supported at two places at the opposite ends thereof by bearings, and a rotation angle sensor for detecting the rotation angle of the shaft is connected to an end portion of the rotation angle detection object shaft. An example of such rotation angle sensor attaching structure is disclosed in the Japanese Patent Laid-Open No. Hei 5-202719.
In such a known rotation angle sensor attaching structure, as described above, where a configuration wherein the rotation angle detection object shaft rotates a plural number of times uses a rotation angle sensor having a detection range of one rotation) (360°), a reduction gear, for reducing the speed of rotation of the rotation angle detection object shaft, is required. As a configuration for providing such reduction gear, it seems appropriate to support the opposite ends of the reduction gear in its axial direction by means of bearings or the like. In this instance, however, in order to support the reduction gear, it is necessary to assure a space in the axial direction of the rotation angle detection object shaft.
The present invention has been made in view of such circumstances as described above. Accordingly, it is one of the objects of the present invention to make it possible to miniaturize a rotation angle sensor attaching structure.